1. Field of the Invention
The present invention relates to a communication apparatus for use with a public telephone network, capable of calling an information supplying terminal device which transmits voice signals in response to a call from a calling party side terminal device, recognizes data transmitted from the calling party side terminal device in response to the voice signals, and transmits information specified by the recognized data, in accordance with predetermined transmitting procedures to the calling party side terminal device.
2. Description of the Related Art
Examples of the communication apparatuses for use with a public telephone network are a telephone set, a facsimile machine and the like. A facsimile machine has a function that, after a telephone number has been inputted to call and connect with a receiving party side terminal device, image signals for representing an image to be transmitted is transmitted, or after the facsimile machine has responded to a call from an other side terminal device and has been connected with the public telephone line, image signals received are outputted as an image.
Recently, information supplying services utilizing such communication apparatus with a public telephone network has been developed. For example, Japanese Unexamined Patent Publication JPA 4-56457 (1991) discloses an example such that when information supplying services are utilized, in response to silent periods which separate a plurality of acoustic signals outputted from the information supplying terminal device, data corresponding to the acoustic signals are automatically transmitted from the calling party side terminal device. Such function is utilized, for example, between a bank and its clients, when the client requests counter transactions of the bank at home by transmitting necessary data through the client's own facsimile or telephone set. A program for inputting and processing the data to be transmitted under the communication, the client's telephone number, and a program for processing memory are stored in an integrated circuit (IC) card or the like. When the IC card is connected to a communication apparatus, the data stored in the IC card is read out and transmitted.
FIG. 12 is a timing chart illustrating an example of signals which are transmitted and received by a conventional communication apparatus which is a calling party side terminal device. First, the communication apparatus calls an information supplying terminal device, which is subsequently connected with a public telephone line. Next, a voice message guidance S4 from the information supplying terminal device is received. The voice message guidance S4 tells, for example, "This is . . . Information Service Center. First, push a button of number 9." In response to the voice message guidance S4, the communication apparatus transmits a dual tone modulation frequency (DTMF) signal D7. Further, the communication apparatus receives a voice message guidance S5. The voice message guidance S5 tells, for example, "Please input a desired box number."In response to the voice message guidance S5, the communication apparatus transmits a DTMF signal D8. Still further, the communication apparatus receives a voice message guidance S6. Such signal transmission and reception are repeated predetermined times. When, in response to a last voice message guidance, a DTMF signal is transmitted, the communication apparatus is put into a standby state by using a information supply request button and the like.
For the purpose of automatic data transmission, the DTMF signals D7, D8 are prestored in the communication apparatus. In the case of automatic transmission, when the received voice message guidance S4 has ended and a predetermined silent period N4 has elapsed, the DTMF signal D7 is transmitted. The information supplying terminal device which has received the DTMF signal D7 transmits the voice message guidance S5 after a processing time P5 required for processing the information supplying terminal device has elapsed. Similarly the communication apparatus which has received the voice message guidance S5 transmits the DTMF signal D8, when the voice message guidance S5 has ended and a predetermined silent period N5 has elapsed. The information supplying terminal device which has received the DTMF signal D8 transmits the voice message guidance S6 after a processing time P6 required for processing the information supplying terminal has elapsed.
In such a communication apparatus, whether a voice signal is outputted is judged relying on the intensity of signal. That is, when a signal of a level lower than a predetermined reference level is continuously obtained for a predetermined period, it is judged that no voice signal is outputted, and when a signal of a higher level than the reference level is obtained, it is judged that a voice signal is outputted. Consequently, when the levels of the voice message guidances S4-S6 are lower than the reference, the communication apparatus transmits a DTMF signal, because it is judged as silent in spite of the fact that the communication apparatus has received the voice message guidances S4-S6.
FIG. 13 is a timing chart illustrating an example of signals transmitted and received in false judgment. First, the communication apparatus calls the information supplying terminal device, and the called information supplying apparatus is connected to the public telephone line. Subsequently, the voice message guidance S4 is transmitted from the information supplying apparatus, though, since the signal level of the voice message guidance S4 received by the communication apparatus is low, it is judged as silent in the communication apparatus, and therefore the communication apparatus transmits the DTMF signal D7 when the predetermined silent period N4 has elapsed after confirmation of the connection with the public telephone line. When the DTMF signal D7 has been transmitted and further the predetermined silent period N5 has elapsed, the DTMF signal D8 is transmitted. The information supplying terminal device which has received the DTMF signal D8 transmits the voice message guidance S7 after the processing period P6 required for processing in the information supplying terminal device. Since the data corresponding to the voice message guidance S4 is not inputted, the voice message guidance S7 tells, for example, "Inputted data can not be identified. Please input again."
As mentioned above, such error operation is caused when no voice signal is detected, for example, when the signal level is reduced depending on the states of the communication apparatus, information supplying terminal device, and public telephone line. It is required of an operator to reinput the data every error operation.
Further, an example of the communication apparatus disclosed in above-mentioned Japanese Unexamined Patent Publication JPA 4-56457 (1991) is for counter transactions of banks whose procedures are predetermined, and therefore obtainable information is limited. When other information is further required, it is necessary to call a party associated with the contents of the information and to establish operation procedures corresponding to each content. The example disclosed in JPA 4-56457 can not respond to such needs and the operator is required to conduct each transmission operation by hand. Thus highly troublesome operations are necessary. Further, in the example of JPA 4-56457, prestored operation programs, telephone numbers to be registered, and DTMF signals to be transmitted are stored in an IC card. The IC card is connected to the communication apparatus, and the stored data is read out and processed. However, for example, when specific processing is specified, inputting by the operator himself is necessary. Thus, in the prior art the operations are not completely automated, troublesome and not-automated operations such as pushing a button in the case of necessity remain.
Still further, since the above-mentioned information supplying services utilizes DTMF signals, a case such that information supply can not be carried out is possible when a line for push button(PB) signals is not used for transmitting and receiving signals. Accordingly, for example, when a line for dial pulse (DP) signals is used, the operator must change over the line to the line for PB signals.